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Abstract:

An airflow management system and/or method used in particle abatement in
semiconductor manufacturing equipment. In particular, the apparatus
disclosed is capable of creating and managing a carefully controlled
particle free environment for the handling of semiconductor wafers or
similar articles. The apparatus is particularly suited to be used as an
interface between an equipment front end module (EFEM) and a vacuum
loadlock chamber or other such article of process equipment. The
apparatus also enables relative motion between enclosures while
maintaining a particle free environment utilizing a moving air diffuser
mounted to an interface panel.

Claims:

1. An air management system configured to form a self-contained system
comprising;an interface panel assembly having a moving air diffuser
associated therewith;wherein the air diffuser is configured to translate
along a path of a process chamber while coupled to the air management
system; andthe air diffuser further comprises vanes generally positioned
to direct airflow in a controlled manner.

2. The air management system of claim 1, wherein the air diffuser is
configured with guide wheels and cam followers.

3. The air management system of claim 1, wherein the interface panel is
configured to guide the air diffuser on a track.

4. The air management system of claim 1, wherein the air diffuser is
further configured with flexible shields attached to the air diffuser and
the shields are pre-tensioned to move in and out of shield housings on
the interface panel as the air diffuser is driven.

5. The air management system of claim 1, wherein the air diffuser is
further configured to diffuse other gases, comprising nitrogen.

6. The air management system of claim 1, wherein a containment shroud is
generally positioned and configured to cover a workpiece platen
associated therewith, wherein the containment shroud is further
configured to hold an exhaust damper in place.

7. The air management system of claim 1, wherein the air diffuser are
configured to attach to the flexible shields with a rotating joint.

8. The air management system of claim 7, wherein the rotating joint
comprises a ball joint, swivel joint and hinge pivot.

9. The air management system of claim 8, wherein air diffuser is connected
to the process chamber with a device, comprising a gear train, a
mechanical linkage and a belt drive.

10. A semiconductor airflow management component, comprising:an interface
panel configured with a structural framework to support and guide a
moveable diffuser;wherein the moveable diffuser is configured translate
along a path allowing a process chamber with the fixedly attached airflow
management component to move relative to an environment front end module;
anda fan filter unit configured for supplying clean air that passes
through the diffuser and over a workpiece platen.

11. The airflow management component of claim 10, wherein the diffuser is
configured with guide wheels and cam followers.

12. The air management component of claim 10, wherein the interface panel
is configured to guide the air diffuser on a track.

13. The air management component of claim 10, wherein the air diffuser is
further configured with flexible shields attached to the air diffuser and
the shields are pre-tensioned to move in and out of shield housings on
the interface panel as the air diffuser is driven.

14. The air management component of claim 10, wherein the air diffuser is
further configured to diffuse other gases, comprising nitrogen.

15. The air management component of claim 10, wherein a containment shroud
is generally positioned and configured to cover a workpiece platen
associated therewith, wherein the containment shroud is configured to
hold an exhaust damper in place.

16. The air management component of claim 10, wherein the air diffuser are
configured to attach to the flexible shields with a rotating joint.

18. A semiconductor implantation system, comprising:an environmental front
end module, an air management system, a processing chamber, and a
reciprocating drive apparatus;wherein the environmental front end module
resides within a first zone configured with a robot to transport a
semiconductor workpiece from the first zone into a second zone through a
moveable diffuser mounted on an interface panel;wherein the moveable
diffuser is configured to translate along a path allowing a process
chamber configured with a fixedly attached airflow management component
surrounding the second zone to move relative to an environment front end
module; anda fan filter unit configured for supplying clean air that
passes through the diffuser from the first zone and over a workpiece
platen in the second zone.

19. The semiconductor implant system of claim 18; wherein the robot is
configured to translate along a course that allows the workpiece to be
passed through the moveable diffuser.

20. The semiconductor implant system of claim 19; wherein the robot moves
along a course comprising a linear pathway and a curvilinear pathway.

21. The semiconductor implant system of claim 18, wherein the moveable
diffuser is configured with guide wheels and cam followers.

22. The semiconductor implant system of claim 18, wherein the interface
panel is configured to guide the air diffuser on a track.

23. The semiconductor implant system of claim 18, wherein the air diffuser
is further configured with flexible shields attached to the air diffuser
and the shields are pre-tensioned to move in and out of shield housings
on the interface panel as the air diffuser is driven.

24. The semiconductor implant system of claim 18, wherein a containment
shroud is generally positioned and configured to cover a workpiece platen
associated therewith, wherein the containment shroud is configured to
hold an exhaust damper in place.

25. The semiconductor implant system of claim 18, wherein the air diffuser
are configured to attach to the flexible shields with a rotating joint.

27. A method for reducing the time to load a semiconductor workpiece in a
process chamber, comprising:rotating semiconductor process chamber to
obtain desired implantation angle;translating air diffuser along arcuate
path in direction opposite process chamber rotation;loading workpiece
from Zone 1 to Zone 2 through air diffuser; andsupplying clean area
within the Zone 1.

28. The method of claim 27, wherein the air diffuser is configured with
guide wheels and cam followers.

29. The method of claim 27, wherein the air diffuser is non-fixedly
attached to an interface panel with a track to guide the air diffuser in
a desired trajectory.

30. The method of claim 27, wherein the air diffuser is further configured
with flexible shields rotatably attached to the air diffuser and the
shields are pre-tensioned to move in and out of shield housings of the
interface panel as the air diffuser is driven.

31. The method of claim 27, wherein the air diffuser is further configured
to diffuse other gases, comprising nitrogen.

32. The method of claim 27, wherein the air diffuser is connected to the
process chamber with a device, comprising a gear train, a mechanical
linkage and a belt drive.

Description:

FIELD OF THE INVENTION

[0001]The present invention relates generally to an apparatus and method
for creating, managing, and maintaining a particle free environment for
the handling of the semiconductor wafers or workpieces. More
particularly, the present invention relates to an enclosed particle free
interface and containment system between the EFEM and a wafer processing
module.

BACKGROUND OF THE INVENTION

[0002]Shortening cycle times to fabricate semiconductors is critical to
the success of semiconductor manufacturing. A key factor in cycle time is
the movement of workpieces from the equipment front end module (EFEM)
into an air management system/load lock area. Shortened cycle times are
critical to operational success allowing lean inventory, better yields,
and the like.

[0003]Semiconductor manufacturing requires an ultra clean environment for
the silicon wafers or workpieces during the manufacturing process;
therefore it is necessary to provide a filtered and controlled airflow of
sufficient velocity to prevent airborne particles from migrating to the
wafer surface, thereby contaminating the wafer and resulting in reduced
production yields. Airflow recirculation near the wafer is significant
source of airborne particles settling on the wafer surface.

[0004]Customers often require that the implantation takes place at an
angle, between zero degrees (0°) and ninety degrees (90°).
In various implantation devices this requires that the process chamber
rotate relative to the stationary ion implanter, for example. Current
technologies and techniques allow for relative motion to occur between
wafer handling apparatus and process modules, however when changing the
implantation angle the process chamber often has to go back into a
position so that new workpieces can be loaded into the load lock area or
air management system. This results in reduced cycle times.

[0005]Thus, it is desirable to provide an apparatus and method for
allowing the relative motion between the process chamber and the air
management system which allows for loading workpieces without the
subsequent movement of the process chamber.

SUMMARY OF THE INVENTION

[0006]The present invention overcomes the limitations of the prior art by
providing an apparatus and method for controlling airflow while allowing
for relative motion to occur between wafer handling and processing
modules. The apparatus consists of a movable diffuser connected to the
containment shroud by means of an interface panel. Airflow between the
modules is controlled by the design of the diffuser and an adjustable
exhaust damper panel at the airflow exit side of the shroud.

[0007]To the accomplishment of the foregoing and related ends, the
invention comprises the features hereinafter fully described and
particularly pointed out in the claims. The following description and the
annexed drawings set forth in detail certain illustrative embodiments of
the invention. These embodiments are indicative, however, of a few of the
various ways in which the principles of the invention may be employed.
Other objects, advantages and novel features of the invention will become
apparent from the following detailed description of the invention when
considered in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1A illustrates an exemplary semiconductor implant system
utilizing an air flow management component and movable air diffuser in
accordance with one aspect of the present invention;

[0009]FIG. 1B illustrates a front perspective view of a reciprocating
drive apparatus according to another aspect of the present invention;

[0010]FIG. 1C is a side view of an exemplary change in the ion
implantation angle on a workpiece according to another aspect of the
present invention;

[0011]FIG. 1D illustrates a side partial cross sectional view of an
exemplary reciprocating drive apparatus system according to another
aspect of the present invention;

[0012]FIG. 1E illustrates a front view of the reciprocating arm in
accordance with still another aspect of the invention;

[0013]FIG. 2A is a top cross sectional view of a process chamber with an
airflow management system in accordance with another aspect of the
present invention;

[0014]FIG. 2B is a top cross sectional view of a process chamber with an
airflow management system and a movable air diffuser according to an
aspect of the invention;

[0015]FIG. 2C is a back perspective view of an interface panel with a
movable diffuser in accordance with another aspect of the invention;

[0016]FIG. 3 is a front view of an interface panel in accordance with
another aspect of the invention;

[0017]FIG. 4 is a top view of an interface panel in accordance with
another aspect of the invention;

[0018]FIG. 5 is a cross-sectional view of the vee bearing assembly
according to an aspect of the invention;

[0019]FIG. 6 is a top perspective view of the interface panel in
accordance with another aspect of the invention;

[0020]FIG. 7A is a cross-sectional side view of the equipment front end
module and the air management system in accordance yet another aspect of
the invention;

[0021]FIG. 7B is a cross-sectional view of airflow within the equipment
front end module and the air management system in accordance with another
aspect of the present invention;

[0022]FIG. 7C is a cross-sectional view of the airflow within the air
management system in accordance with still another aspect of the present
invention;

[0023]FIG. 8 is a graph of the average the filter of velocity versus the
fan filter units power, in accordance with an aspect of the present
invention;

[0024]FIG. 9 is a graph of differential pressure versus the load lock
damper opening percentage, according to yet another aspect of the present
invention;

[0025]FIG. 10 is a graph of differential pressure versus load lock damper
opening with lower damper opened at 100%, in accordance with yet another
aspect of the present invention;

[0026]FIG. 11 is a graph of Zone 1 differential pressure relative to Zone
2 differential pressure with the floor damper opened 100%, in accordance
with still another aspect of the present invention;

[0027]FIG. 12 is a graph of Zone 1 differential pressure relative Zone 2
with the floor damper opened at 50%, in accordance with another aspect of
the invention;

[0028]FIG. 13 is a graph of flow velocity normal to the interface diffuser
floor damper, according to yet still another aspect of the present
invention;

[0029]FIG. 14 is a graph of flow velocity normal to the interviews
diffuser floor damper, according to another aspect of the present
invention;

[0030]FIG. 15 is a flow chart illustrating an exemplary air management
technique according to yet another aspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0031]The present invention is directed generally toward a reduced cycle
time airflow management system and method for controlling particle
abatement in semiconductor manufacturing equipment. Accordingly, the
present invention will now be described with reference to the drawings,
wherein like reference numerals may be used to refer to like elements
throughout. It should be understood that the description of these aspects
are merely illustrative and that they should not be interpreted in a
limiting sense. In the following description, for purposes of
explanation, numerous specific details are set forth in order to provide
a thorough understanding of the present invention. It will be evident to
one skilled in the art, however, that the present invention may be
practiced without these specific details.

[0032]Referring now to the figures, in accordance with one exemplary
aspect of the present invention, FIG. 1A illustrates an exemplary
semiconductor implantation system 100 comprising an equipment front end
module (EFEM) 102, an air management system (AMS) 104 and an exemplary
reciprocating drive system (RDS) 106. The EFEM 102 is a component in
semiconductor automation, moving work pieces between a "dirty" processing
areas and "clean" areas, for example. Equipment front end modules 102
were developed in response to the requirement for higher yields, faster
throughput, contamination reduction, and the like, while maintaining
ever-shrinking geometries in the semiconductor industry. Contamination
levels that were acceptable a short time ago are no longer acceptable for
many products.

[0033]The equipment/environmental front end module 102 can be configured
with a shroud (not shown) defining a protected environmental area where
work pieces may be reached and handled with minimum potential for
contamination of the workpiece. In one embodiment the EFEM 102 comprises
a robot 112 with robotic arms 114 for holding and moving a workpiece (not
shown) and an air management system 104 for circulating air around a
workpiece. The robot 112 in this embodiment can translate along a
pathway, for example, linear, curvilinear, and the like, or the robot 112
in another embodiment can be stationary. In addition, robotic arms 114
can translate or rotate or both, for example. It will be understood that
the EFEM 102 of FIG. 1A can be configured to move the workpiece from a
"clean" zone 1 or first zone (108), illustrated in FIG. 1A, as a dashed
line, into a zone 2 or second zone (110) within the air management system
104.

[0034]The exemplary airflow management system 104 comprises a shroud 116,
an interface panel 118 configured with a moving diffuser 120, and an
adjustable damper 122, wherein the moving diffuser 120 is generally
configured with vanes 124. The moving diffuser 120 provides an opening
between Zone 1 (108) and inside the AMS 104 referred to as Zone 2 (110).
The AMS 104 further comprises a support surface or platen 126 for
supporting the workpiece, wherein the moving diffuser 120 is configured
to move in order to align the translating robot 112 and the robotic arms
114, the air diffuser 120 and the platen 126 within the chamber interior
of Zone 2 (110). The air management system 104 can be fixedly attached to
a rotating process chamber 128, for example.

[0035]According to the present invention, the reciprocating drive
apparatus (RDS) 106 can be located within and extending through the
process chamber 128, for example. FIG. 1A illustrates the outside of the
process chamber 128, for example. The chamber 128 may comprise a
generally enclosed vacuum chamber 128, wherein an internal environment
within the process chamber is operable to be generally isolated from an
external environment outside the process chamber. For example, the vacuum
chamber 128 can be configured and equipped so as to maintain the internal
environment at a substantially low pressure (e.g., a vacuum). The process
chamber 128 may be further coupled to one or more load lock chambers,
well known by those of ordinary skill in the art, wherein the workpiece
may be transported between the internal environment of the process
chamber 128 and the external environment, Zone 1 (108) without
substantial loss of vacuum within the process chamber 128. The process
chamber 128 may alternatively be comprised of a generally non-enclosed
process space, wherein the process space is generally associated with the
external environment.

[0036]FIGS. 1B, 1D and 1E illustrate simplified views of an exemplary
reciprocating drive apparatus 130 operable within a process chamber 128
to reciprocally translate or oscillate a workpiece 132 along a
predetermined first scan path 134. The process chamber 128 is used with
an exemplary air management system 104, according to one aspect of the
present invention. It should be noted that the reciprocating drive
apparatus 130 of FIGS. 1B, 1D and 1E is illustrated to provide an
upper-level understanding of the invention, and is not necessarily drawn
to scale. Accordingly, various components may or may not be illustrated
for clarity purposes. It shall be understood that the various features
illustrated can be of various shapes and sizes, or excluded altogether,
and that all such shapes, sizes, and exclusions are contemplated as
falling within the scope of the present invention. Additionally, the air
management system 104 can be configured to operate with the
non-reciprocating drive system, for example, and is a key in the present
invention.

[0037]As implied by the use of the term "reciprocating drive apparatus",
in one example, the drive apparatus 130 of the present invention,
illustrated in FIG. 1B is operable to reciprocally translate or oscillate
the workpiece 132 in a reversible motion along the first scan path 134,
such that the workpiece translates alternatingly back and forth with
respect to a generally stationary ion beam 147 or 148, wherein the
apparatus can be utilized with the air management system 104 in an ion
implantation process, as will be discussed hereafter in greater detail.
Alternatively, the air management system 104 and the reciprocating drive
apparatus 130 may be utilized in conjunction with various other
processing systems, which may include other semiconductor manufacturing
processes such as, for example, a step-and-repeat lithography system. In
yet another alternative, the air management system 104 can be utilized in
various processing systems not related to semiconductor manufacturing
technology, and all such systems and implementations are contemplated as
falling within the scope of the present invention.

[0038]According to one aspect of the present invention, the reciprocating
drive apparatus 130 comprises a motor 136 operably coupled to a scan arm
138 wherein the scan arm is further operable to support the workpiece 132
thereon. The motor 136, for example, comprises a rotor 140 and a stator
142, wherein the rotor 140 and the stator 142 are dynamically coupled and
operable to individually rotate about a first axis 144. The rotor 140 is
further operably coupled to a shaft 146, wherein the shaft 146 generally
extends along the first axis 144 and is operably coupled to the scan arm
138. In the present example, the rotor 140, the shaft 146, and the scan
arm 138 are generally fixedly coupled to one another, wherein rotation of
the rotor 140 about the first axis 144 generally drives rotation of the
shaft 146 and scan arm 138 about the first axis 144, thus generally
translating the workpiece 132 along the first scan path 134.
Alternatively, the rotor 140, the shaft 146, and the scan arm 138 may be
otherwise coupled to one another, wherein the rotation of the rotor 140
and/or shaft 146 may drive an approximate linear translation of the scan
arm 138 with respect to the first axis 144, as will be further discussed
infra.

[0039]In one example, a process medium, such as the ion beam 148 (FIG.
1C), serves as the generally stationary reference, wherein the process
chamber 128 is operable to move with respect to the process medium 148,
for example, rotate about a second axis 154 (FIGS. 1B, 1D) and angle
θ 149. The process medium 148, for example, may be alternatively
associated with other semiconductor processing technologies. For example,
the process medium 148 may comprise a light source associated with a
lithography process. Accordingly, the present invention contemplates any
process chamber 128 and process medium 148 operable to be utilized in
processing the workpiece 132 (FIG. 1D), whether the process chamber 128
be enclosed, non-enclosed, fixed, or transitory, and all such process
chambers and process mediums are contemplated as falling within the scope
of the present invention.

[0040]In accordance with another exemplary aspect of the invention, the
motor 136 comprises a rotor 140 and a stator 142 (FIG. 1D), wherein the
rotor 140 and the stator 142 are operable to individually rotate about a
first axis 144, and wherein an electromagnetic force between the rotor
140 and the stator 142 generally drives a rotation of the rotor 140 about
the first axis 144. For example, a control of the electromagnetic force
between the rotor 140 and the stator 142 is operable to selectively drive
the rotation of the rotor 140 in a clockwise or counter-clockwise
direction about the first axis 144, as will be discussed infra. In
another example, the motor 136 further comprises a motor housing 156,
wherein the motor housing 156 is generally stationary with respect to the
first axis 144. The motor housing 156 in the present example generally
encases the rotor 140 and stator 142 and further generally serves as the
generally stationary reference for the rotation of the rotor 140 and
stator 142. A least a portion of the rotor 140 and stator 142 generally
reside within the motor housing 156, however, the motor housing 156 need
not enclose the rotor 140 and the stator 142. Accordingly, the rotor 140
and the stator 142 are operable to individually rotate with respect to
the motor housing 156, wherein the motor housing 156 is further operable
to generally support the rotor 140 and the stator 142 therein. It should
be noted that while the present example describes the motor housing 156
as being the generally stationary reference, other generally stationary
references may be alternatively defined.

[0041]The motor 136, in one example, comprises a brushless DC motor, such
as a three-phase brushless DC servo motor. The motor 136, for example,
may be sized such that a substantially large diameter of the motor (e.g.,
a respective diameter of the stator 140, and/or the rotor 142) provides a
substantially large torque, while maintaining a moment of inertia
operable to provide rapid control of the rotation of the rotor 142. The
reciprocating drive system 130 further comprises a shaft 146 operably
coupled to the motor 136, wherein in one example, the shaft 146 is
fixedly coupled to the rotor 140 and generally extends along the first
axis 144 into the process chamber 128. Preferably, the rotor 140 is
directly coupled to the shaft 135, as opposed to being coupled via one or
more gears (not shown), wherein such a direct coupling maintains a
substantially low moment of inertia associated with the rotor, while
further minimizing wear and/or vibration that may be associated with the
one or more gears.

[0042]According to another example, the process chamber 128 comprises an
aperture 157 therethrough, wherein the shaft 146 generally extends
through the aperture 157 from the external environment 158 to the
internal environment 159, and wherein the motor 136 generally resides in
the external environment 158. Accordingly, the shaft 146 is operable to
rotate about first axis 144 in conjunction with the rotation of the rotor
140, wherein the shaft 146 is generally rotatably driven by the rotor 140
in alternating, opposite directions. In the present example, the shaft
146 may be substantially hollow, thereby providing a substantially low
inertial mass. Likewise, the rotor 140 may be substantially hollow,
further providing a substantially low rotational inertial mass.

[0043]One or more low-friction bearings 150, for example, are further
associated with the motor 136 and the shaft 146, wherein the one or more
low-friction bearings rotatably couple one or more of the rotor 140, the
stator 142, and the shaft 146 to a generally stationary reference 152,
such as the housing 146 or the process chamber base 160. The one or more
low-friction bearings 150, for example, generally provide a low
coefficient of friction between the respective rotor 140, stator 142,
shaft 146, and motor housing 156. In another example, at least one of the
one or more low-friction bearings 150 may comprise an air bearing (not
shown), a liquid field environment, or other bearing known in the art.

[0044]In accordance with another exemplary aspect of the invention, the
reciprocating drive apparatus 130 is partitioned from the process chamber
128, such that minimum wear and contamination occurs within the internal
environment 162. For example, the shaft 146 is generally sealed between
the process chamber 128 and the external environment 158 by a rotary seal
associated with the shaft and the process chamber, wherein the internal
environment 162 within the process chamber is generally isolated from the
external environment.

[0045]The reciprocating drive apparatus system 160 further comprises a
scan arm 138 operably coupled to the shaft 146, wherein the scan arm 138
is operable to support the workpiece 132 thereon. According to another
example, the scan arm 138 comprises an elongate arm 164 extending
radially from the first axis 144, wherein the elongate arm 164 is
generally fixedly coupled to the shaft 146, wherein the rotation of the
shaft 146 about the first axis generally translates the workpiece 132
with respect to the first axis 144. In one example, the scan arm 132 is
coupled to the shaft 146 at a center of gravity of the scan arm 132,
wherein the scan arm 132 is substantially rotationally balanced about the
first axis 144. In another example, the scan arm 132 is comprised of a
light weight material, such as magnesium or aluminum.

[0046]The scan arm 138 may further comprise an end effector 135 operably
coupled thereto, whereon the workpiece 132 is generally supported
thereon. The end effector 135, for example, comprises an electrostatic
chuck (ESC) or other workpiece clamping device is operable to selectively
clamp or maintain the workpiece 132 with respect to the end effector 135.
The end effector 135 may comprise various other devices for maintaining a
grip of the workpiece 132, such as a mechanical clamp or various other
retaining mechanisms as may be known by those of ordinary skill in the
art, and all such devices are contemplated as falling within the scope of
the present invention.

[0047]In another example, the scan arm 138 may further comprise a
counterweight 166 operably coupled thereto, wherein the counterweight 166
generally balances a mass of the scan arm 138, end effector 135, and the
workpiece 132 about the first axis 144. Such a counterweight 166 may
advantageously assist in centering the mass moment of inertia of the scan
arm 138 about the first axis 144, thus dynamically balancing the scan arm
138 about the first axis 144. Accordingly, the scan arm 138, shaft 144,
rotor 140, and stator 142 are generally dynamically balanced about the
first axis 144, thus generally eliminating side load forces, other than
gravitational forces. The counterweight 166, for example, may be
comprised of heavier metal than the scan arm 138, such as steel.

[0048]In the case where the reciprocating drive apparatus 130 of the
present invention is utilized in an ion implantation system, the
reciprocating drive apparatus 130 may further comprise a load lock
chamber/air management system 104 associated with the process chamber
128, wherein scan arm 138 is further operable to rotate and/or translate
the end effector 135 to the load lock chamber/AMS 104 in order to insert
or remove workpieces 132 to or from the process chamber. Furthermore, a
Faraday cup 167 is provided within the process chamber 138 and positioned
within a path of the ion beam 148, wherein the Faraday cup 167 is
operable to generally sense a beam current associated with the ion beam
148. Accordingly, the sensed beam current can be utilized for subsequent
process control.

[0049]According to another exemplary aspect, the end effector 135 may be
rotatably coupled to the scan arm 138 about a second axis 160, wherein
the end effector 135 is operable to rotate about the second axis. An end
effector actuator 170 may be operably coupled to the scan arm 138 and the
end effector 135, wherein the end effector actuator 170 is operable to
rotate the end effector 135 about the second axis 168. The second axis
168, for example, is generally parallel to the first axis 144, wherein
the process chamber 128 may be operable, for example, to selectively
rotate the workpiece 132 relative to the ion beam 148 to vary the
so-called "twist angle" of implant, as will be understood by those of
ordinary skill in the ion implantation art. The process chamber 128 can
be rotated about the third axis 172, an angle θ 149, for example,
forty five degrees (45°) to implant the workpiece 132 at that
angle as illustrated in FIGS. 1B and 1C. Alternatively, the rotatable
coupling of the end effector 136 to the scan arm 138 may be utilized to
maintain a rotational orientation (e.g., a rotational orientation 174 of
FIG. 1E) of the workpiece 136 with respect to the ion beam 148 by
continuously controlling the rotation of the end effector 135 about the
second axis 154. The end effector actuator 176 of FIG. 1D may comprise a
motor (not shown) or mechanical linkage (not shown) associated with the
scan arm 138 operable to maintain the rotational orientation of the
workpiece 132 with respect to the ion beam 148. Alternatively, the end
effector actuator 176 may comprise a pivot mount (not shown) associated
with the second axis 154 (240), wherein inertial forces associated with
the workpiece 132 are operable to maintain the rotational orientation of
the workpiece 132 with respect to the ion beam 148. Maintaining the
rotational orientation of the workpiece 132 with respect to the ion beam
148 is advantageous when the ion beam 148 impinges on the workpiece 132
at a non-orthogonal angle θ 149, and/or when a crystalline or other
structure associated with the workpiece (e.g., a semiconductor substrate,
or a substrate having structures formed thereon) plays a role in the
uniformity of the ion implantation.

[0050]According to another aspect of the present invention, a robot 112
can pick up a workpiece from a storage component (not shown) in the first
zone 108 and translate it into a second zone 110. The robot 112 can be
stationary or it can translate along a linear or curvilinear path (not
shown). The workpiece can be grasped utilizing robotic arms 114 that are
able to translate or rotate, as is well known by those of ordinary skill
in the art.

[0051]Referring now to FIG. 1E an exemplary rotation 178 of the shaft 146
about the first axis 144 of FIG. 1D is illustrated, wherein the scan arm
138, end effector 135, and workpiece 132 are further rotated about the
first axis 144. Accordingly, the workpiece 132 can be reciprocally
translated along a first scan path 180 with respect to the ion beam 148
(e.g., via one or more cyclical counter-rotations of the shaft 146 about
the first axis 144), wherein the ion beam 148 of FIGS. 1B, 1C and 1D is
illustrated as going into the page of FIG. 1E. The rotation 178 (and
counter-rotation) of the shaft 146 about the first axis 144 can be
advantageously controlled in order to oscillate or reciprocate the end
effector 135 along the first scan path 180 in a uniform manner, as will
be discussed hereafter. FIG. 1E further illustrates a rotation 178 of the
end effector 135 about the second axis 154 as discussed above, wherein
the rotation 178 of the end effector 135, and hence, the workpiece 132,
about the second axis 154 can be further controlled in order to maintain
the rotational orientation 174 of the workpiece 132 with respect to the
first axis 144 or ion beam 148 (e.g., rotational orientation of the
workpiece 132 with respect to the ion beam 148 is indicated by a triangle
174 that is fixed with respect to the workpiece 132).

[0052]In order to evenly process the workpiece 132, such as providing an
even implantation of ions into the workpiece 132 from the ion beam 148,
it is important to maintain a generally constant translational velocity
of the end effector 135 when the workpiece 132 is subject to the ion beam
148 while traveling along the first scan path 180. Maintaining a
generally constant velocity of the end effector 135 while the workpiece
132 passes through the ion beam 148, for example, provides a generally
uniform dose of ions to the workpiece 132, thus evenly processing the
workpiece 132 as it travels along the first scan path 180 in a
pendulum-type motion.

[0053]Therefore, in one embodiment, a generally constant velocity is
desired for a predetermined scanning range 182 associated with the
movement of the workpiece 132 through the ion beam 148. The predetermined
scanning range 182 is generally associated with the physical dimensions
of the workpiece 132 (e.g., greater than a diameter D of the workpiece).
In the present example, the predetermined scanning range 184 is generally
defined by the workpiece 132 traveling a distance greater than a total of
the diameter D of the workpiece plus a width of the ion beam 148, wherein
the workpiece 132 travels through the ion beam 148 along the first scan
path 180, and wherein the ion beam 148 is relatively scanned between
opposite ends 184 of the workpiece.

[0054]According to another embodiment, a desired velocity profile for the
workpiece 132 within the predetermined scanning range 182 may be defined,
wherein the desired velocity profile generally depends on a configuration
of the reciprocating drive apparatus 130. For example, depending on
whether the workpiece 132 is fixed or rotatable with respect to the scan
arm 138, a respective generally constant velocity or a variable velocity
of the rotation 178 of the scan arm (and thus, a respective generally
constant or variable velocity of the workpiece 132 along the first scan
path 180) may be desired. If, for example, the workpiece 132 is rotated
with respect to the scan arm 138 in order to maintain the rotational
orientation 174 along the first scan path 180, the rotational velocity of
the scan arm about the first axis 144 may be varied when the ion beam 148
nears ends 184 of the predetermined scanning range 182 (e.g., an increase
in velocity by about 10% near the ends 184 of the predetermined scan
range 184) in order to provide a generally uniform dose of ions to the
workpiece 132 along the curvilinear path 178. As another alternative, or
in addition to varying the velocity of the scan arm 138, properties of
the ion beam 148, such as the ion beam current, can be varied in order to
produce a generally uniform dosage of ions to the workpiece 132.

[0055]FIGS. 2A and 2B illustrate simplified views of an exemplary process
chamber system 200 and 250, respectively operable to rotate the process
chamber 128 around a process chamber axis 204. It should be noted that
the main difference between FIG. 2A and FIG. 2B is that the air diffuser
202 of FIG. 2A is illustrated as a fixed or stationary air diffuser 202,
whereas the air diffuser 120 of FIG. 2B is a moving air diffuser 120
illustrated to provide an upper-level understanding of the invention, and
is not necessarily drawn to scale. Accordingly, various components may or
may not be illustrated for clarity purposes. It shall be understood that
the various features illustrated can be of various shapes and sizes, or
excluded altogether, and that all such shapes, sizes, and exclusions are
contemplated as falling within the scope of the present invention.

[0056]As implied by the use of the term "moving air diffuser ", in one
example, the process chamber 128 of the present invention, illustrated in
FIGS. 2A and 2B are operable to rotate about the process chamber axis
154, such that the workpiece rotates with respect to a generally
stationary ion beam, wherein the apparatus can be utilized with an air
management system 104 in an ion implantation process, as will be
discussed hereafter in greater detail. Alternatively, the air management
system 104 and the moving air diffuser 120 may be utilized in conjunction
with various other processing systems, which may include other
semiconductor manufacturing processes such as, for example, a
step-and-repeat lithography system. In yet another alternative, the air
management system 104 can be utilized in various processing systems not
related to semiconductor manufacturing technology, and all such systems
and implementations are contemplated as falling within the scope of the
present invention.

[0057]According to one aspect of the present invention, the process
chamber 130 of FIGS. 2A and 2B is driven by a motor operably coupled to a
gearbox wherein the motor is further operable with a spur gear, for
example, to rotate the process chamber, thereon. The air diffuser 202 of
FIG. 2A is fixedly attached, for example, to the air management system
104 which is attached to and rotates with the process chamber 128. In
other words, in FIG. 2A, the process chamber 128, the air management
system 128, and the air diffuser 202 are generally fixedly coupled to one
another, wherein rotation of the process chamber 128 about the axis 204
generally drives rotation of the AMS 104 and the air diffuser 202 about
the axis 204. As illustrated in FIG. 2A, the center of the air diffuser
202 initially starts out at angle α 206 which in this example is
zero degrees (0°), for example. A customer may request an ion
implantation angle of forty five degrees (45°) as described supra.
When the process chamber 128 in FIG. 2A is rotated clockwise forty five
degrees (45°) (angle β 208) the air management system 104 and
the air diffuser 202 rotate clockwise forty five degrees (45°), as
well.

[0058]FIG. 2A illustrates a robot 112 having a robotic arm 114 for loading
workpieces between an equipment/environmental front end module (EFEM) 102
and AMS 104, that were described in detail supra. As illustrated, the
robot is able to load the workpieces when the process chamber is at angle
α (0°) however the robot 112 is unable to load workpieces at
angle β (45°) because the air diffuser 202, the interface
opening between the EFEM 102 and the AMS 104, is too far away. In this
case the process chamber has to be rotated counterclockwise from angle
β 208 to a predetermined angle that is less than angle β 208
and greater than or equal to angle α 206. This additional movement
of the process chamber 128 increases cycle times or the need for
additional robots, for example, at a time when manufacturers are being
driven to reduce cycle times for processing wafers and manufacturers want
to limit the floor space allocated to robotics, process chambers and the
like. Therefore a need clearly exists to reduce cycle time and allocated
equipment space.

[0059]Alternatively, the system 250 illustrated in FIG. 2B meets the goals
outlined above utilizing a moving air diffuser 120, as will be further
discussed infra. FIG. 2B is a simplified top cross-sectional view of an
exemplary process chamber system 250 similar to the one shown in FIG. 2A,
however, the air diffuser 120 is mechanically coupled to the process
chamber 128 so that they rotate in opposite directions to each other. The
mechanical coupling can be executed using a belt drive, a gear train, a
mechanical linkage and the like. As seen in FIG. 2B, the air diffuser 120
is generally integral to an air transfer system 104, wherein the air
diffuser 120 is generally configured to translate along a path allowing a
process chamber to rotate relative to the equipment front end module. The
translation in this embodiment is along an arcuate path, however any path
is contemplated within this invention, for example, a linear path, a
sinusoidal path, a predefined path, etc. The air diffuser 128 further
comprises vanes 124 that are shaped and generally positioned to direct
airflow in a controlled manner from the outside to the inside of the AMS
104 illustrated in FIG. 2A. The air diffuser 120 is further configured
with a moveable linkage configured to drive the air diffuser 120 in the
direction opposite of the direction the process chamber 128 is being
driven, for example.

[0060]As illustrated in FIG. 2B, the process chamber starts out, for
example, at angle α (0°) and is rotated 45°
clockwise, wherein the air diffuser 120 is driven counterclockwise
22.5°, for example. As illustrated in FIG. 2B, in contrast to
system 200 in FIG. 2A, a robot 112 can load a workpiece into the air
management system 104 when the process chamber 128 has been rotated
clockwise 450 because the air diffuser 120 has rotated counterclockwise
22.5°, for example. In yet another alternative, the air diffuser
120 can be designed so that the air diffuser 120 rotates in the direction
opposite of the process chamber 128 by the same number of degrees, or in
various ratios, and the like. The ratio of the relative angular movement
of the process chamber 128 and the air diffuser 120 can be adjusted by
adjusting the gearing ratio, for example. Of course, those skilled in the
art will recognize many modifications may be made to this configuration,
without departing from the scope or spirit of what is described herein,
and all such systems and implementations are contemplated as falling
within the scope of the present invention.

[0061]FIGS. 2C, 3, 4, 5 and 6 illustrate various views of the exemplary
interface panel 120 of FIG. 1A. The interface panel 120 is shown in
greater detail, wherein further exemplary aspects of the present
invention can be appreciated. FIG. 2C illustrates a top front perspective
view, wherein the interface panel 120 and a moving air diffuser 106 are
illustrated, wherein the moving air diffuser 106 and the interface panel
260 are coupled to each other via respective vee wheels 126 (FIG. 5) and
cam followers 204, wherein the wheels 126 translate along an arcuate
track 230. The vee wheels 126 and cam followers 204, for example, are
configured to rotate thereby translating the air diffuser 106 along the
same arcuate path. The air diffuser 106 is connected to movable shields
134 on both sides of the diffuser 106. The moveable shields 134 are
preloaded in tension wherein the shield 134 is either pulled out of or
retracted into a shield housing(s) 214. Thus, the air diffuser 106 is
movable about the interface panel 260 therein allowing access of a
robotic arm from outside the air management system to enter the air
management system illustrated in FIG. 1A after the process chamber 128
has been rotated. The shield 134 prevents air from passing through the
interface panel 134 at locations where the shield 134 is located, for
example. One or more motors, linkages or other force-producing mechanisms
(not shown) may be further operably coupled to one or more of the
interface panels 120 and the process chamber 128, wherein controlled
rotation of the process chamber 128 and the moving air diffuser 106 may
be attained. For example, the controller 151 of FIG. 1D may be further
configured to selectively position (e.g., rotate or translate) the
process chamber 128 thirty five degrees (35°) clockwise and air
diffuser 120 thirty five degrees (35°) counterclockwise (e.g., by
controlling the motor(s) coupled to the linkage), therein generally
controlling the position of the air diffuser 106 relative to the
stationary robot, for example. FIG. 3 illustrates a front view of the
interface panel 300 illustrated in FIG. 2C, for example. FIG. 5 is a
section view B-B as illustrated in FIG. 4. The vee wheel 126 is
illustrated, wherein the vee wheel 126 rides on and is "captured" by the
track 230, for example. The vee wheel 126 can be flexibly held in place
using a modified shoulder screw 235 preloaded with disc springs 231 and
232, for example that are well known by those of ordinary skill in the
art. It is to be appreciated that the interface panel 120 can be
constructed in numerous ways, for example, utilizing folding panels,
motors and wireless communication, and the like.

[0062]FIG. 7A illustrates an exemplary air management system 700 discussed
above, wherein the air management system 700 comprises an interface panel
and a moving air diffuser 120 of FIG. 2C, for example. The diffuser 120
comprises vanes 124, for example, configured to direct air entering the
EFEM 102 from a fan unit 714 at the upper end of the EFEM 102, wherein
the air (e.g., illustrated as a dashed arrows) is directed through the
air diffuser 120 by vanes 124 that direct the air over a platen 126,
wherein particles and/or contaminants are directed away from the
workpiece 132. In one embodiment, a first vane can be set at sixty
degrees (60°, angle δ), to horizontal, the second vane can
be set at twenty five degrees (60°, angle ε) to
horizontal, a third vane can be set at minus sixty degrees (-60°,
angle ζ), and the fourth vane may be set to minus twenty five
degrees (-25°, angle η). The height of the opening 716 can be
fabricated to 305 mm, for example, with the dimensions for the fourth
vane 718 and 720, as shown. As illustrated the dimension 718 is 40 mm and
the dimension is 20 mm, for example. It is to be appreciated that of
course, those of ordinary skill in the art will recognize many
modifications may be made to this configuration, without departing from
the scope or spirit of what is described herein, for example, six vanes,
equal vane angles, etc. In addition other fluids than air are
contemplated e.g., nitrogen, and the like in the present invention and
may be utilized with other types and configurations of air management
systems 104 without departing from the spirit and the scope of the
invention.

[0063]FIG. 7B illustrates a cross-sectional view of the environmental
front end module 102 as it interfaces with the air management system 104.
A moving air diffuser 120 is comprised of vanes 124 that are optimized to
re-circulate air above the workpiece so that contaminants, coming in
contact with the workpiece in Zone 2 (110), are minimized. A fan unit 714
supplies clean air to be EFEM 102 that passes through the air diffuser
120 and over at a workpiece platen 124 which then exits the air
management system 104 through an adjustable damper 122. FIG. 7B
illustrates a flow optimization that was performed using a flow
simulation, for example. The pressure between Zone 1 (108), Zone 2 (110)
and Zone 3 (111) is maintained to ensure a desired air flow velocity of
air that is well-known by one of ordinary skill in the art.

[0064]FIG. 7C illustrates a semi-transparent cross-sectional view of an
air management system 104. A moving air diffuser 120 is comprised of
vanes 124 that are optimized to re-circulate air above the workpiece so
that contaminants, coming in contact with the workpiece in Zone 2 (110),
are minimized. A fan unit supplies clean air that passes through the air
diffuser 120 and over at a workpiece platen 124 which then exits the air
management system 104 through an adjustable damper 122. FIG. 7C
illustrates a flow optimization that was performed using a flow
simulation, for example. The FIG. 7C illustrates that the flow of air
over the top of the platen 124 is basically laminar which tends to drive
contaminants away from the workpiece. The air flow/pressure tests agree
with Computational Fluid Dynamics (CFD) models as a good approximation to
be described infra.

[0065]Referring to FIG. 8, in one embodiment of the present invention, is
a graph at 800 that illustrates representative filter face velocities
that were obtained, comparing both average filter velocity (fpm) and
velocity uniformity (%) vs. fan filter units power (%). The graph
illustrates the data, as plotted on a linear x-axis, and a linear y-axis.
The graph 800 includes two different exemplary groupings of curves 802
and 804, the first curve 802 was obtained by fixing the fan filter unit
power at three different levels (e.g., 50%, 75% and 100%) of capacity.
The average filter velocity was measure at each of those power levels.
The second curve 804 is representative three data points plotted based on
velocity uniformity at the three power points discussed supra. For
example, it can be seen in the curve 802; the system can deliver a
maximum of approximately 112 fpm average velocity. Also it is apparent
that at approximately 90% of the FFU power and above the velocity
uniformity is approximately about 10% or less which meets specification
to prevent air flow recirculation.

[0066]In yet another test, according to one embodiment of the present
invention, three groups of data 902, 904 and 906 were obtained for an air
management system, as shown in FIG. 7C as a graph 900, for example. The
graph illustrates Zone 1 (110) to ambient (111) differential pressure,
utilizing a floor damper 777 (e.g., FIG. 7C), for example, that is open
50%. The curves 902, 904, and 906 illustrate the differential pressure
(wg) obtained with the fan filter unit 714 (FIG. 7B) at 100%, 75% and
50%, respectively and the damper open at 0%, 25%, 50%, 75%, and 100%.
Data 902 illustrates that with the floor damper 50% open and the load
lock damper closed (0%).

[0067]According to another embodiment a test, three groups of data 1002,
1004 and 1006 were plotted for an air management system, as shown in FIG.
7C as a graph 1000, for example. The graph illustrates Zone 1 (110) to
ambient (111) differential pressure, utilizing a floor damper 777 (e.g.,
FIG. 7C), for example, that is open 100%. The curves 1002, 1004, and 1006
illustrate the differential pressure (wg) obtained with the fan filter
unit 714 (FIG. 7B) at 100%, 75% and 50% power, respectively and the
damper open at 0%, 25%, 50%, 75%, and 100%. Data 902 illustrates that
with the floor damper 50% open and the load lock damper closed (0%).
FIGS. 9 to 14 defines the range the tool operation which a desirable flow
across the diffuser could be maintained.

[0068]In yet an additional test, according to yet another embodiment of
the present invention, three groups of data 1102, 1104 and 1106 were
attained for graph 1100 for an air management system, as discussed supra.
The graph 1000 illustrates Zone 1 (110) to Zone 2 (108) differential
pressure, utilizing a floor damper 777 (e.g., FIG. 7C), for example, that
is 100% open. The curves 1102, 1104, and 1106 illustrate the differential
pressure (wg) obtained with the fan filter unit 714 (FIG. 7B) at 100%,
75% and 50%, respectively and the load lock damper open at 0%, 25%, 50%,
75%, and 100%. FIG. 12 illustrates data similar to the data in FIG. 11
except the floor damper is set at 50% open.

[0069]Referring to FIG. 13, in yet another embodiment of the present
invention, is a graph 1300 that illustrates representative flow velocity
normal to the interface diffuser with the floor damper at 100% open, that
were obtained, comparing both average interface flow velocity (fpm) and
velocity (m/s) vs. load lock damper open (%). The graph illustrates the
data, as plotted on a linear x-axis, and a linear y-axis. The graph 1300
includes three different exemplary groupings of curves 1302 and 1304, and
1306. The point 1308 on curve 1308 is the CFD modeled condition with an
average horizontal velocity of 0.5 m/sec. In other words, at 1.0 Pa, the
average interface velocity was calculated using the model to equal 0.502
m/sec, whereas the actual test result at 1.04 Pa was 0.502 m/sec.
Therefore the theoretical and the test rest are approximately equal. FIG.
14 is similar to FIG. 13 except the floor damper, discussed supra is set
at 50% open, for example.

[0070]According to still another exemplary aspect of the present
invention, FIG. 15 is a schematic block diagram of an exemplary method
1500 illustrating a method of minimizing the contaminants that settle on
a workpiece as the workpiece is moved from the EFEM to a load lock
chamber while reducing the cycle time in loading the workpiece. The block
diagram FIG. 15 is according to an exemplary air management system e.g.,
FIGS. 1D and 7C. While exemplary methods are illustrated and described
herein as a series of acts or events, it will be appreciated that the
present invention is not limited by the illustrated ordering of such acts
or events, as some steps may occur in different orders and/or
concurrently with other steps apart from that shown and described herein,
in accordance with the invention. In addition, not all illustrated steps
may be required to implement a methodology in accordance with the present
invention. Moreover, it will be appreciated that the methods may be
implemented in association with the systems illustrated and described
herein as well as in association with other systems not illustrated.

[0071]As illustrated in FIG. 15, the method 1500 begins with rotating the
semiconductor processing chamber to a desired angle to correspond to an
ion implantation angle at 1502, for example. The processing chamber, for
example, comprises an air management system fixedly attached to the
chamber for diffusing air across a workpiece loaded inside the air
management system or Zone 2. The air management system comprises a
shroud, an interface panel configured with a moving diffuser, wherein the
moving diffuser is generally configured with air deflecting vanes, and an
adjustable damper configured to control the pressure within Zone 2. The
moving diffuser provides an opening between Zone 1, the
equipment/environmental front end module outside the air management
system (AMS). The AMS further comprises a support surface or platen for
supporting the workpiece, wherein the moving diffuser is configured to
move in order to align a workpiece motion device, e.g., robot, the air
diffuser and the platen within the chamber interior of Zone 2 resulting
in a reduced workpiece loading time.

[0072]At 1504 the air diffuser is translated along an arcuate path, for
example. The air diffuser and process chamber can be driven separately
using motors and wireless communication, for example, or the drive
rotating the process chamber can also drive a linkage or a gear train for
example that drive the air diffuser in a direction opposite to the
process chamber. The inventors recognized the advantage of the moveable
air diffuser (e.g., FIGS. 1D and 2C) that allowed the movement of the
process chamber and yet allowed the concurrent movement of the air
diffuser so that transfer mechanisms within the EFEM had immediate access
to the load lock chamber platen, for example, thereby reducing cycle
times. At 1506 the transfer device, for example, a pick and place robotic
arm transfers the workpiece from Zone 1 through the air diffuser opening
and into Zone 2.

[0073]The robot at 1508 can then place the workpiece on a platen and clean
air is then supplied by a fan filter unit passes from Zone 1 through the
air diffuser opening and deflected by the vanes. The air exits through
the adjustable load lock damper and/or a floor damper. The method ends at
1508.

[0074]Accordingly, the present invention provides a faster cycle time for
ion implantation, especially in systems where moving the process chamber
relative to the EFEM is performed. It should be further noted that
although the invention has been shown and described with respect to a
certain preferred embodiment or embodiments, it is obvious that
equivalent alterations and modifications will occur to others skilled in
the art upon the reading and understanding of this specification and the
annexed drawings. In particular regard to the various functions performed
by the above described components (assemblies, devices, circuits, etc.),
the terms (including a reference to a "means") used to describe such
components are intended to correspond, unless otherwise indicated, to any
component which performs the specified function of the described
component (i.e., that is functionally equivalent), even though not
structurally equivalent to the disclosed structure which performs the
function in the herein illustrated exemplary embodiments of the
invention. In addition, while a particular feature of the invention may
have been disclosed with respect to only one of several embodiments, such
feature may be combined with one or more other features of the other
embodiments as may be desired and advantageous for any given or
particular application.